Datasheet
PRELIMINARY
UB20.241
U–Series
24V, 20A, DC-UPS
Fig. 7-3 Short-circuit on output, hiccup mode, typical behavior
Output
Current
0
30A
17s
17s17s 2s 2s2s
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8. BATTERY INPUT
The DC-UPS requires VRLA batteries with a sum voltage of 24V which is usually achieved by a series connection of two
12V batteries. To extend the service lifetime of the battery, the point of connection of the batteries can be connected
with the center tap of the DC-UPS. (See chapter 27.3)
Battery voltage
nom. 2x DC 12V Use two maintenance-free 12V VRLA lead acid batteries
in series
Allowed battery sizes min. 3.9Ah At battery selector <10Ah
max 130Ah At battery selector position >10Ah
Battery charging method CC-CV Constant current, constant voltage mode
Battery charging current (CC-mode) nom. 3.0A at battery selector >10Ah, see also chapter 14
max 3.2A
nom 1.5A at battery selector <10Ah, see also chapter 14
max 1.6A
End-of-charge-voltage (CV-mode)
13.4V
13.4-
14.2Vdc*)
If no temperature sensor is connected to the unit
If an analog temperature sensor or PULS battery module
is connected to the optional terminal
Battery charging time typ. 8h**) For a 12Ah battery
Deep discharge protection ***) typ. 10.5V*) At 0A output current
typ. 9.0V*) At 20A output current
Min. battery voltage
typ. 7.4Vdc*) Above this voltage level battery charging is possible
*) These values are valid for each connected battery.
**) The charging time depends on the duration and load current of the last buffer event. The numbers in the table represent a
fully discharged battery.
***) To ensure longest battery lifetime, the DC-UPS has a battery deep discharge protection feature included. The DC-UPS stops
buffering when the voltage of one battery falls below a certain value.
September 2012 / Rev. 1.3 DS-UB20.241-EN preliminary
All parameters are specified at an input voltage of 24V, 20A output load, 25°C ambient and after a 5 minutes run-in time
unless otherwise noted. It is assumed that the input power source can deliver a sufficient output current.
www.pulspower.com Phone +49 89 9278 0 Germany
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